Plating solution pickup unit

ABSTRACT

Apparatus for use with an electroplating machine and a plating solution reclaiming unit having a plurality of reservoirs for receiving rinse system effluent and plating solution from the plating machine and controlling their flow to the reclaiming unit.

United States Patent Streeter 1 1 Jan. 23, 1973 [541 PLATING SOLUTIONPICKUP UNIT 3,358,706 l2/l967 Tischbein ..l37/263 l,866,472 7/1932Knowles Hl37/263 X [75] Inventor streete" lnd'anapohs 2,250,130 7 1941May ..137/398 x [73] Assignee: Dean Brothers Pumps, Inc., Indianapolis,FOREIGN PATENTS OR APPLICATIONS Oct. l,l78,727 7/l957 France ..l37/263PP 765,919 Primary Examiner-M. Cary Nelson Assistant ExaminerRobert J.Miller 52 us. 01 ..l37/263, 137/398 Atwmekwilliam Streeter 51 1111.01...B0lf 5/00, GOlg 5/00 581 Field of Search ..137/101.27, 263, 265, 571,ABSTRACT 137/574 398 Apparatus for use with an electroplating machineand a plating solution reclaiming unit having a plurality of [56]References cued reservoirs for receiving rinse system effluent and plat-UNITED STATES PATENTS ing solution from the plating machine andcontrolling their flow to the reclaiming unit. 2,626,446 1/1953 Moore..l37/263 X 3,135,288 6/1964 Leisenheimer ..l3l/263 X 10 Claims, 6Drawing Figures l- L Z2 23 a PATENTEDJAH23 1975 3,712,329

B ERT STE EETER PLATING SOLUTION PICKUP UNIT BACKGROUND OF THE INVENTIONThe dragout effect in metal electroplating machines results in theremoval ofa portion of each liquid bath in which the parts to be platedare immersed and its conveyance into the subsequent liquid bath intowhich the parts are immersed due to the liquids adhering to and beingentrapped by the parts and the conveying apparatus of the platingmachine. The dragout effect results in substantially equal volumes ofliquid being carried into and out of each successive bath as the partsand conveying apparatus are sequentially immersed therein. In theplating tank, for example, preplating solution is carried into theplating solution, and plating solution is carried out of the platingtank into the rinse water of the first rinse tank. The effect is todilute the concentration of plating solution in the plating tank withoutdecreasing the volume of liquid in the plating tank, except as thevolume may be reduced by evaporating to the atmosphere.

In plating operations where the dragout rate exceeds the evaporationrate, for example in a barrel type plating machine plating zinc orcadmium, returning reclaimed plating solution (concentrate) to theplating tank at the same concentration as that desired in the platingtank would cause a net increase in the volume of liquid in the platingtank, because the volume of concentrate which would have to be added islarger than the volume of water that is evaporated from the platingtank. This is especially true in plating solutions where the operatingtemperature is generally below 130 F. The return of concentrate withoutremoval of some of the plating solution from the tank would eventuallyresult in overflowing the sidewalls ofthe plating tank.

It is practicable to reduce the liquid volume of the concentratereturned to the plating tank by increasing its concentration, but onlyto a limited extent, because at high concentrations the plating solutionchemicals tend to crystallize and clog pipes and valves. It is furtherpracticable and desirable to remove plating solution from the platingtank while returning concentrate thereto in order to maintain both thedesired concentration and liquid level in the plating tank.

The present invention provides an apparatus for removing platingsolution from the plating tank as concentrate is added thereto, and doesso in a manner that precludes accidentally removing an excess of platingsolution from the plating tank. The apparatus is adapted to mix the flowof plating solution removed from the plating tank with the flow of rinsesystem effluent to the reclaiming unit, and may be adapted to deliverplating solution to the reclaiming unit, when because of surges in therinse system and intermittent plating machine operation, there may be noeffluent flow for varying periods of time.

The present invention also provides a great amount of versatility in theoperation of a reclaiming unit by providing a means whereby a pluralityof electroplating machines plating the same metal at the same ordifferent plating solution concentrations and having different rinsesystem flow rates may be serviced by a single reclaiming unit. Thisimprovement, heretofore believed unattainable, results not only inversatility, but also achieves additional economies both in equipmentcost and in operating expenses.

SUMMARY OF THE INVENTION The apparatus of the present invention,hereinafter referred was a pickup unit, may include a first reservoirarranged to receive the overflow of effluent from the rinse system, asecond reservoir for receiving plating solution from the plating tankand adapted to overflow into a third reservoir that drains into thefirst reservoir, thereby limiting the volume of plating solution thatmay be taken from the plating tank. A first conduit leads from near thebottom of the first reservoir to the reclaiming unit. A float operatedvalve in the first conduit is adapted to open as the liquid level in thefirst reservoir rises and to close as it falls, going fully closed at aliquid level above the top of the float operated valve. This preventsany air from entering the first conduit and being carried to thereclaiming unit should there be a leak around the operating stem of thefloat operated valve, It is highly undesirable to admit anyuncondensible gasses, are contained in air, to a reclaiming unit, suchas that described in my copending application, Ser. No. 621,604, filedMar. 8, 1967 now abandoned.

The pickup unit may also include a fourth reservoir between the rinsesystem and the first reservoir, which may overflow into the firstreservoir via a weir notch that may be used to measure the effluent flowrate. A second float operated valve may be added to the pickup unit toadmit makeup water to the system when it is needed.

The addition of a concentration measuring device in connection with apickup unit permits the use of a single plating solution reclaiming unitwith a plurality of plating machines plating the same metal in differentconcentration plating solutions. Also, the rinse systems of thedifferent plating machines served by the one reclaiming unit may havedifferent flow rates.

It is therefore an object of the present invention to provide animproved apparatus for use with plating solution reclaiming units.

lt is another object of the present invention to provide a'piekup unitadapted to receive effluent and plating solution from a plating machine,mix the two, and control the flow thereof to a reclaiming unit.

It is still another object of the present invention to provide a fullyautomatic pickup unit which will meet the liquid requirements of areclaiming unit without permitting air to enter the pickup unit.

Still another object of the present invention is to provide a pickupunit that will automatically add makeup water to the effluent when it isrequired.

Yet another object of the present invention is to provide a method orprocess for use with plating machines and reclaiming units wherebygreater control and versatility may be achieved.

Another object ofthe present invention is to provide a method andapparatus whereby a plurality of plating machines may be served by asingle reclaiming unit, and wherein the plurality of plating machinesmay be operated with different effluent flow rates and plating solutionconcentrations.

These and other objects and advantages will become apparent as thedescription proceeds, reference being had to the attached drawings andappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic plan viewshowing a portion of the tanks of a plating machine and the generalrelationship thereto of the pickup unit of the present invention.

FIG. 2 is a somewhat diagrammatic cross-sectional elevation view showingthe hydraulic relationship of the pickup unit of the present inventionto the plating tank and a rinse tank of an electroplating machine.

FIG. 3 is a generally perspective view of one assembly of the pickupunit of the present invention.

FIG. 4 is a diagrammatic illustration showing how the pickup unit of thepresent invention permits one reclaiming unit to serve a plurality ofplating machines.

FIG. 5 is an electrical schematic diagram showing one control circuitwhich may be used with the arrangement illustrated in FIG. 4.

FIG. 6 is a generally diagrammatic cross-sectional view of anotherembodiment of the pickup unit of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, thereis shown diagrammatically a plan view ofa portion of the tanks ofaplating machine. The tanks may include a preplating tank 11, a platingtank 12 which may have stations l3, l4 and 15 and a counterflow rinsesystem 21, having tanks 22, 23 and 24. The parts to be plated areconveyed by a conveying means (not shown) sequentially through the tanksand stations from left to right.

Because of the dragout effect, preplating solution from tank 11 iscarried into the plating tank 12 and plating solution is carried out ofthe plating tank 12 into the rinse tank 22. The volumes carried into andout of the plating tank by the dragout effect are substantially equal,thereby substantially maintaining the liquid level in the plating tankconstant while at the same time diluting the concentration of theplating solution with preplating solution.

In the counterflow rinse system 21, fresh water is admitted to tank 24,tank 24 overflows into tank 23, tank 23 overflows into tank 22, and thecontaminated rinse water (effluent) is removed from tank 22. It will beseen that tank 22 will contain the highest concentration of platingsolution and tank 24 will contain the lowest.

As disclosed in my copending application, Ser. No. 621,604, filed Mar.8, 1967, now abandoned the effluent withdrawn from tank 22 may be runthrough a plating solution reclaiming unit where the plating solution isreclaimed and distilled water or distillate made available to be reusedin the rinse system. The reclaimed plating solution or concentrate maybe returned to the plating tank.

Because the dragout effect does not reduce the volume of platingsolution in the plating tank, but

merely dilutes it, if the rate of evaporation is small, as it generallyis in cyanide plating solutions, the addition of concentrate to theplating tank tends to increase the volume of liquid in the plating tank.Thus, it is necessary to remove plating solution from the plating tankto make room for the reclaimed plating solution so that the plating tankwill not overflow.

Processes have been used in the past wherein a volume of platingsolution is withdrawn from the plating tank, placed in a heated vessel,and water evaporated therefrom. The equipment used in these processeshastaken its suction directly from the plating tank, and has on occasionwithdrawn an excess of plating solution from the plating tank. This hastwo possible deleterious effects. First, the plating solution may escapethrough an overflow pipe from the heated vessel and be drained to asewer or stream. Second, the level of plating solution in the platingtank may be lowered below the minimum operating level so that theplating machine must be shut down until the plating solution level israised.

The pickup unit of the present invention solves each of these problemsby providing automatic withdrawal of the proper amount of platingsolution from the plating tank, and does so by overflow means thatprevent lowering the level in the plating tank below the minimumoperating level.

FIG. 2 shows one embodiment of the pickup unit of the present invention,indicated generally at 30, located adjacent the last station 15 of theplating tank 12 and the first rinse tank 22. The pickup unit 30 may havethree reservoirs 31, 32 and 33. The reservoirs 32 and 33 may be formedby an assembly 36 having a generally cylindrical sidewall 37, a bottom38 and a partition 39 that generally vertically bisects the assembly 36.A conduit 41 connects reservoir 32 to the plating tank 12 at a pointbelow the minimum normal operating level 42 of the plating solution.Conduit 41 preferably slopes so that it may be rodded out easily whensludge or precipitates collect in it.

FIG. 3 shows a generally perspective view of the assembly 36 wherein thepartition 39 has a V-notch weir located in its upper margin. The bottomof the V-notch is located at the same elevation as the minimum normaloperating level 42 of the plating solution in the plating tank 12. Itwill be seen from the arrangement of the reservoirs 32 and 33 that whenplating solution is above the level 42 it will flow through conduit 41into reservoir 32 and overflow into reservoir 33. Because of thecharacteristic of the V-notch, the higher the level above level 42, thegreater the flow rate from reservoir 32 to reservoir 33. Standard weirformulas may be used to calculate the flow rate of plating solutionthrough the V-notch.

Reservoir 31 is formed by an open top vessel 43 which may be supportedby legs 44. A conduit 45, which is preferably formed of flexible tubingor hose to facilitate breaking up any sludge or plating solutionchemical precipitates that may collect therein, connects the bottom ofreservoir 33 to reservoir 31. Another conduit 46 connects rinse tank 22to reservoir 31 as shown in FIG. 2. The connection of conduit 46 to tank22 is located at the desired liquid level 48 so that effluent willoverflow from tank 22 into reservoir 31 As with the connection to theplating tank, conduit 46 provides an overflow type of connection,thereby eliminating the possibility of drawing the level of rinse waterin tank 22 down too low. If no measure of the plating solution flow rateis desired, the vessel 36 and reservoirs 32 and 33 could be omitted, theconnection to the plating tank being made, in a manner similar to theconnection to the rinse tank, at the normal minimum operating level.

As a safety precaution, the upper margins of reservoirs 31, 32 and 33should be made substantially the same height as the plating tank 12 andthe rinse tank 22. This is because the volumes of the reservoirs arecomparatively small in relation to the volumes of the plating and rinsetanks. When a load of parts being plated or rinsed is lowered into theplating or rinse tanks, the liquid displaced could cause the reservoirsto overflow onto the floor if their margins were not high enough.

A conduit 51 extends downwardly into reservoir 31 to a point near thebottom. At its lower end is a strainer 52. Its other end is connected toa plating solution reclaiming unit, to be more fully describedsubsequently. Just above the strainer 52 is a valve 53 that is operatedthrough a linkage 54 by a float 55. The valve 53 is adapted to open asthe liquid level in reservoir 31 rises and to close as it falls, thevalve 53 going fully closed before it is exposed to the air. In thismanner, should the operating stem of valve 53 leak, no air would bepermitted to enter the conduit 51 and be admitted to the reclaimingunit.

Because of space limitations immediately adjacent the plating and rinsetanks of many plating machines, it is impossible to locate all thereservoirs of the pickup unit in close proximity to the plating andrinse tanks. In such cases, the assembly 36 may be mounted directly onthe side of the plating tank by suitable mounting means. The conduits 45and 46 may be formed of flexible hose or tubing for ease of handling androuting, as well as for ease of cleaning as noted above.

In operation, rinse system effluent flows from rinse tank 22 throughconduit 46 into reservoir 31, where, so long as the liquid level issufficiently high to maintain valve 53 open, it is drawn into conduit 51and conveyed to the reclaiming unit. This flow is generally continuous,except for momentary surges when parts are immersed in the rinse tanksand momentary stoppages when the parts are withdrawn from the rinsetanks. The flow of plating solution from the plating tank 12 throughconduit 4land reservoir 32 and over the partition 39 into reservoir 33and into reservoir 31 via conduit 45 is somewhat intermittent. As statedearlier, the dragout effect does not substantially change the volume ofplating solution in the plating tank, but merely dilutes it. Thealternate immersion and withdrawal of parts to be plated as they aremoved from station to station through the plating tank, does, however,cause the liquid level of plating solution in the plating tank to changerather abruptly. This can result in surges of plating solution tendingto flow through assembly 36 to reservoir 3!, and may on occasion,substantially raise the liquid level in reservoir 31. The action of theweir notch in partition 39, however, tends to reduce the effect ofsurges from the plating tank and cause a generally more even flow ofplating solution to the reservoir 31.

When only one plating machine is connected to a reclaiming unit, as isfully disclosed in my copending application, Ser. No. 621,604, filedMar. 8, 1967, now abandoned a pickup unit 30 may be used advantageouslyto receive the rinse system effluent and plating solution from theirrespective tanks, providing a measurement of the flow rates if desired,and controlling their flow to the reclaiming unit. When it is desired touse a single reclaiming unit with two or more plating machines, thepickup unit and method of the present invention makes such operationpossible.

Referring now to FIG. 4, there is shown a partial diagrammatic plan viewof three plating machines, indicated at A, B and C. Each plating machinehas a plating tank 12, with stations 13, 14 and 15, rinse tanks 22, 23and 24, and a pickup unit 30, lower case letters being used to identifyeach element to its particular plating machine. Also associated witheach plating machine is a distillate valve 56, a concentrate valve 57,and a concentration measuring device 58, which may be arranged tomeasure the concentration of plating solution in the plating tank 12.All three plating machines are served by a single reclaiming unit 65. Aconduit 66 carries distillate from the reclaiming unit to the rinsesystems and a conduit 67 carries concentrate from the reclaiming unit tothe plating tanks.

The concentration measuring device 58 may be of any of the types knownto the art, however, one form that has been found to work quitesatisfactorily is shown in FIG. 2, and includes a bob 71 supported -by aline 72 affixed to one end of a lever arm 73, the other end of which isadapted to receive weights 74 in much the same manner as a beam balance.The bob 71, which is preferably conical at its upper end to help preventany buildup thereon of sludge or precipitate that would alter itsoverall specific gravity, is provided with a specific gravity somewhatheavier than the specific gravity of the plating solution at the desiredconcentration. The weights 74 are then chosen to partiallycounterbalance the bob 71 so that when the concentration of the platingsolution is at the desired value the lever arm 73 is balanced. When theconcentration falls below or rises above the desired value, the bob 71descends and rises respectively. The arm 73 is affixed near its centerto a shaft 75 that operates an electrical switch 76. To protect the bob71, it may be suspended within a perforated plastic tube 77.

In operation, the valves 56 are adjusted to proportion the flow ofdistillate to each of the rinse systems as desired. Each tank 24overflows into tank 23, which overflows into tank 22, which overflowsinto reservoir 31 of pickup unit 30. The flow of distillate to eachrinse system is substantially constant, however, the flow of effluent toeach reservoir 31 is not constant as a result of the conveying apparatusand parts being rinsed being periodically immersed in and removed fromthe rinse tanks, causing surges of effluent flow separated by periods ofsubstantially no flow. The flow of concentrate to the plating tank, onthe other hand, is not constant, but varies with the concentration ofthe plating solution in the plating tank. When the concentration of theplating solution in the plating tank falls below the desiredconcentration, bob 71 will descend, operating switch 76, which in turnopens valve 57 to admit concentrate to the plating tank. As concentrateis added to the plating tank to increase the concentration of theplating solution therein to the desired concentration, the liquid levelin the plating tank rises. This causes plating solution to flow intoreservoir 32 and overflow into reservoir 33 from which it drains intoreservoir 31 and mixes with the effluent. Valve 53 controls the flow ofmixture to the reclaiming unit and prevents any air from entering theline 51.

In the arrangement of FIG. 4, the reclaiming unit 65 may be providedwith a concentrate storage tank wherein concentrate is stored untilneeded. A concentration measuring device 78 on the reclaiming unit,which may be similar to the devices 58,maintains the concentration ofthe concentrate in the storage tank at a higher value than that of thehighest desired concentration plating solution. By way of illustration,assume that plating machine A, which may be a barrel type machine, hasthe highest desired concentration plating solution and plating machineC, which may be a rack type machine, has the lowest. Then theconcentrate produced by the reclaiming unit must have a concentrationhigher than that of the plating solution in plating machine A.

It will be seen that when the concentration of the plating solution inplating machine C (lowest concentration) falls below its desired value,only a relatively small volume of concentrate need be added to bring theconcentration up to the desired value. On-the other hand, when theconcentration of the plating solution in line A falls below its desiredvalue, a somewhat larger volume of concentrate must be added to bringthe concentration up to the desired value. This fact makes it generallypossible and desirable to use the highest concentration plating tank asthe storage tank, eliminating any need for a separate storage tankassociated with the reclaiming unit. In this case, concentrationmeasuring device 78 is connected to the concentrate valve 57 of theplating line having the highest concentration plating solution, in thepresent illustration, valve 57a. When this is done, concentrationmeasuring device 580 may be dispensed with.

In .such an arrangement, the electrical connections shown in FIG. may beused to interconnect the concentration measuring devices 58 and 78 andthe valves 57, where each valve 57 has an operating coil 81 andconcentration measuring device 78 operates a switch 82. A conductor 84and a conductor 85 are connected to a power supply 86. Switch 82 has oneside connected to conductor 84 and the other side connected to one sideof coil 81a, one side of switch 76b and one side of switch 76c. Theother side of switch 76b is connected to one side of coil 81b and theother side of switch 76c is connected to one side of coil 810. The othersides of coils 81a, 81b and 810 are connected to conductor 85. Thus,whenever the reclaiming unit 65 has concentrate available, concentrationmeasuring device 78 closes switch 82 to energize coil 81a and open valve57a to admit concentrate to plating tank 12a. When the concentration ofplating solution in the plating tanks of plating machines B or C fallsbelow the desired value, switch 76b or 76c respectively will close toenergize its respective coil 81b or 810, providing that concentrate ispresently available from the reclaiming unit 65, in.

which case switch 82 will be closed. As soon as each plating solutionconcentration is brought up to the desired value, each switch 76 willopen, causing its respective valve 57 to close.

Thus, it will be seen that the desired concentrations of platingsolution are maintained in each of the plating machines A, B and C, allserved by one reclaiming unit 65.

Referring now to FIG. 6, there is shown another em bodiment of thepickup unit of the present invention wherein there is an assembly havingreservoirs 31', 32, 33' and 94. The reservoirs are connected in relationto the plating tank 12 and rinse tank 22 in the same relationship as thecorrespondingly numbered reservoirs in FIG. 2. Reservoir 94 with itspartition 96 may be used to provide a weir for measuring the flow ofeffluent to the pickup unit. In operation, the pickup unit of FIG. 6receives plating solution into reservoir 32" from the plating tank 12.The plating solution overflows the partition between reservoir 32 and33' into reservoir 33'. This partition mayhave its upper margin, or thebottom ofa weir notch in its upper margin, located at the same elevationas the minimum normal operating level 42 of plating solution in theplating tank I2. A partition between reservoirs 33 and 31' may have itsupper margin at the average normal operating level 95 of platingsolution in the plating tank 12. The partition 96 has its upper marginat the desired overflow level 48 of rinse water in rinse tank 22, andpermits effluent to overflow into reservoir 31. A float operated valve53 in reservoir 31 operates in substantially the same manner as valve 53of FIG. 2, to control the flow of plating solution and effluent throughthe conduit 51. A conduit 97 may be provided between a point near thebottom of compartment 33' and conduit 51 and having therein a remotelyoperated valve 98.

In operation, the pickup unit of FIG. 6 will normally have platingsolution filling reservoirs 32' and 33' and overflowing into reservoir31. Effluent will be overflowing partition 96 into reservoir 31'. Theliquid level in reservoir 31 will be between its upper and lower limits,the lower limit being determined by the level at which valve 53' isfully closed. If the flow of effluent should cease, and the liquid levelin reservoir 31 be drawn down to the minimum, closing valve 53', noliquid would be available to the reclaiming unit through conduit 51. If,during such a condition, liquid were required by the reclaiming unit forits proper operation, a liquid level control device on the reclaimingunit could open valve 98 to admit plating solution to conduit 51' tosatisfy the reclaiming units liquid requirements. In the event that thevolume of plating solution above the minimum normal operating level wasin-v adequate to fully supply the reclaiming units liquid requirementsbefore additional effluent from the rinse system were available, itwould be desirable to add makeup water to the system. This may easily beaccomplished by a float operated valve 99 located in reservoir 33' andadapted to close as the liquid level in reservoir 33' rises and to openas the liquid level falls. To prevent air from entering the conduit 51'and being admitted to the reclaiming unit, the valve 99 should beconnected to a makeup water supply capable of supplying makeup waterfaster than the reclaiming unit can receive liquid through conduit Slsothat the lower end of conduit 97 is never exposed to the air.

It will be seen that themethod and apparatus of the present inventionaccomplish all of the objects set forth above and while the inventionhas been illustrated and described in detail in the drawings andforegoing description, the same is to be considered as illustrative andnot restrictive in character, it being understood that only thepreferred embodiments have been shown and described and that all changesand modifications that come within the spirit of the invention and thescope of the claims are also desired to be protected.

For example, where the normal operating level of plating solution in theplating tank is higher than the normal operating level of rinse water inthe adjacent rinse tank, a check valve 100 may be installed at theoutlet of conduit 46 to prevent plating solution from flowing into therinse tank should the reclaiming unit stop taking liquid through conduit51 and reservoir 31 become filled with plating solution.

The invention claimed is:

1. A pickup unit for use with a plating solution reclaiming unit and aplating machine having a plating tank and at least one rinse tank, saidpickup unit comprising receiving means for receiving effluent from therinse tank and for receiving plating solution from the plating tank,first control means for controlling the flow of effluent from the rinsetank to the receiving means, second control means for controlling theflow of plating solution from the plating tank to the receiving means,and third control means for controlling the flow of effluent and platingsolution from the receiving means to the reclaiming unit, said firstcontrol means comprising effluent overflow means for permitting a flowof effluent to the receiving means only when the level of rinse water inthe rinse tank is above a predetermined rinse water level.

2. A pickup unit for use with a plating solution reclaiming unit and aplating machine having a plating tank and at least one rinse tank, saidpickup unit comprising receiving means for receiving effluent from therinse tank and for receiving plating solution from the plating tank,first control means for controlling the flow of effluent from the rinsetank to the receiving means, second control means for controlling theflow of plating solution from the plating tank to the receiving means,and third control means for controlling the flow of effluent and platingsolution from the receiving means to the reclaiming unit, said secondcontrol means being adapted to permit a flow of plating solution fromthe plating tank to the receiving means only when the level of platingsolution in the plating tank is above a predetermined plating solutionlevel.

3. The invention according to claim 2 wherein the second control meanscomprises an assembly having two reservoirs separated by a partition,means for connecting one of the reservoir to the plating tank tomaintain plating solution in said one reservoir at the same level as theplating solution in the plating tank, the other reservoir beingconnected to the receiving means, and the upper margin of the partitionbeing adapted to permit plating solution to overflow from the onereservoir to the other reservoir when the level of plating solution inthe plating tank and in the one reservoir is above the predeterminedplating solution level.

4. The invention according to claim 3 wherein the upper margin of thepartition has therein a weir notch, the bottom of the notch being at thepredetermined plating solution level.

5. A pickup unit for use with a plating solution reclaiming unit and aplating machine having a plating tank and at least one rinse tank, saidpickup unit comprising receiving means for receiving effluent from therinse tank and for receiving plating solution from the plating tank,first control means for controlling the flow of effluent from the rinsetank to the receiving means, second control means for controlling theflow of plating solution from the plating tank to the receiving means,and third control means for controlling the flow of effluent and platingsolution from the receiving means to the reclaiming unit, and whereinthe receiving means comprises a first reservoir; the first control meanscomprises overflow means for permitting a flow of effluent to the firstreservoir when the level of rinse water in the rinse tank is above apredetermined rinse water level; the second control means comprises asecond reservoir and a third reservoir separated by a partition adaptedto permit plating solution to overflow from the second reservoir to thethird reservoir when the level of plating solution in the plating tankand in the second reservoir is above a predetermined plating solutionlevel; and the third control means comprises a valve responsive to theliquid level in the first reservoir, the valve being adapted to open asthe liquid level rises and to close as the liquid level falls.

6. The invention according to claim 5 wherein said first control meanscomprises a fourth reservoir for receiving effluent from the rinse tank,said fourth reservoir being separated from the first reservoir by asecond partition for permitting effluent to overflow from the fourthreservoir to the first reservoir when the level of rinse water in therinse tank and in the fourth reservoir is above the predetermined rinsewater level.

7. The invention according to claim 5 wherein the third reservoir isseparated from the first reservoir by a third partition adapted topermit plating solution to overflow from the third reservoir to thefirst reservoir when the level of plating solution in the plating tankand in the second and third reservoirs is above a second predeterminedplating solution level.

8. A pickup unit for use with a plating solution reclaiming unit and aplating machine having a plating tank and at least one rinse tank, saidpickup unit comprising receiving means for receiving effluent from therinse tank and for receiving plating solution from the plating tank,first control means for controlling the flow of effluent from the rinsetank to the receiving means, second control means for controlling theflow of plating solution from the plating tank to the receiving means,and third control means for controlling the flow of effluent and platingsolution from the receiving means to the reclaiming unit, and means forsupplying the reclaiming unit with plating solution when no effluent isavailable.

9. The invention according to claim 8 further comprising means forautomatically adding makeup water to the pickup unit when no effluent isavailable and no plating solution is available.

10. The invention according to claim 1 further comprising check valvemeans for preventing the flow of any liquids from the receiving means tothe rinse tank.

1. A pickup unit for use with a plating solution reclaiming unit and aplating machine having a plating tank and at least one rinse tank, saidpickup unit comprising receiving means for receiving effluent from therinse tank and for receiving plating solution from the plating tank,first control means for controlling the flow of effluent from the rinsetank to the receiving means, second control means for controlling theflow of plating solution from the plating tank to the receiving means,and third control means for controlling the flow of effluent and platingsolution from the receiving means to the reclaiming unit, said firstcontrol means comprising effluent overflow means for permitting a flowof effluent to the receiving means only when the level of rinse water inthe rinse tank is above a predetermined rinse water level.
 2. A pickupunit for use with a plating solution reclaiming unit and a platingmachine having a plating tank and at least one rinse tank, said pickupunit comprising receiving means for receiving effluent from the rinsetank and for receiving plating solution from the plating tank, firstcontrol means for controlling the flow of effluent from the rinse tankto the receiving means, second control means for controlling the flow ofplating solution from the plating tank to the receiving means, and thirdcontrol means for controlling the flow of effluent and plating solutionfrom the receiving means to the reclaiming unit, said second controlmeans being adapted to permit a flow of plating solution from theplating tank to the receiving means only when the level of platingsolution in the plating tank is above a predetermined plating solutionlevel.
 3. The invention according to claim 2 wherein the second controlmeans comprises an assembly having two reservoirs separated by apartition, means for connecting one of the reservoir to the plating tankto maintain plating solution in said one reservoir at the same level asthe plating solution in the plating tank, the other reservoir beingconnected to the receiving means, and the upper margin of the partitionbeing adapted to permit plating solution to overflow from the onereservoir to the other reservoir when the level of plating solution inthe plating tank and in the one reservoir is above the predeterminedplating solution level.
 4. The invention according to claim 3 whereinthe upper margin of the partition has therein a weir notch, the bottomof the notch being at the predetermined plating solution level.
 5. Apickup unit for use with a plating solution reclaiming unit and aplating machine having a plating tank and at least one rinse tank, saidpickup unit comprising receiving means for receiving effluent from therinse tank and for receiving plating solution from the plating tank,first control means for controlling the flow of effluent from the rinsetank to the receiving means, second control means for controlling theflow of plating solution from the plating tank to the receiving means,and third control means for controlling the flow of effluent and platingsolution from the receiving means to the reclaiming unit, and whereinthe receiving means comprises a first reservoir; the first control meanscomprises overflow means for permitting a flow of effluent to the firstreservoir when the level of rinse water in the rinse tank is above apredetermined rinse water level; the second control means comprises asecond reservoir and a third reservoir separated by a partition adaptedto permit plating solution to overflow from the second reservoir to thethird reservoir when the level of plating solution in the plating tankand in the second reservoir is above a predetermined plating solutionlevel; and the third control means comprises a valve responsive to theliquid level in the first reservoir, the valve being adapted to open asthe liquid level rises and to close as the liquid level falls.
 6. Theinvention according to claim 5 wherein said first control meanscomprises a fourth reservoir for receiving effluent from the rinse tank,said fourth reservoir being separated from the first reservoir by asecond partition for permitting effluent to overflow from the fourthreservoir to the first reservoir when the level of rinse water in therinse tank and in the fourth reservoir is above the predetermined rinsewater level.
 7. The invention according to claim 5 wherein the thirdreservoir is separated from the first reservoir by a third partitionadapted to permit plating solution to overflow from the third reservoirto the first reservoir when the level of plating solution in the platingtank and in the second and third reservoirs is above a secondpredetermined plating solution level.
 8. A pickup unit for use with aplating solution reclaiming unit and a plating machine having a platingtank and at least one rinse tank, said pickup unit comprising receivingmeans for receiving effluent from the rinse tank and for receivingplating solution from the plating tank, first control means forcontrolling the flow of effluent from the rinse tank to the receivingmeans, second control means for controlling the flow of plating solutionfrom the plating tank to the receiving means, and third control meansfor controlling the flow of effluent and plating solution from thereceiving means to the reclaiming unit, and means for supplying thereclaiming unit with plating solution when no effluent is available. 9.The invention according to claim 8 further comprising means forautomatically adding makeup water to the pickup unit when no effluent isavailable and no plating solution is available.
 10. The inventionaccording to claim 1 further comprising check valve means for preventingthe flow of any liquids from the receiving means to the rinse tank.